An electrophotographic image forming apparatus such as a printer, a copier, or a multifunction printer has a toner cartridge, detachably mounted therein, which contains toner for use in a printing process, and the toner contained in the toner cartridge is gradually consumed every time a printing process is performed. When the toner cartridge is emptied, the image forming apparatus have the empty toner cartridge replaced by a toner cartridge full of toner.
FIG. 1 shows an internal structure of a conventional toner cartridge yet to be mounted into an image forming apparatus. As shown in FIG. 1, the toner cartridge 100 includes: a housing 101 for containing toner, a dropping outlet 102, provided on a bottom surface of the housing 101, via which the toner contained in the housing 101 is dropped out of the housing 101; a toner conveying screw 103, provided in the housing 101, which conveys the toner close to the dropping outlet 102; and a drive gear 104 linked to the toner conveying screw 103. The toner cartridge 100 further includes: a shutter 105 placed on an outside wall of the housing 101 so as to cover the dropping outlet 102 externally; and a heat seal 106 sandwiched between the dropping outlet 102 and the shutter 105.
According to the foregoing arrangement, before the toner cartridge 100 is mounted into the image forming apparatus, the heat seal 106 and the shutter 105 seal the dropping outlet 102 externally so as to prevent the toner from leaking through the dropping outlet 102. When a user pulls out the heat seal 106 from the toner cartridge 100 and places the toner cartridge 100, from which the heat seal 106 has been pulled out, into the image forming apparatus, the shutter 105 slides automatically so that the dropping outlet 102 is exposed and the toner contained in the housing 101 flows into a developing device (not shown) of the image forming apparatus via the dropping outlet 102.
(Patent Document 1)
Japanese Unexamined Patent Application Publication No. 57936/2003 (Tokukai 2003-57936; published on Feb. 28, 2003)
Immediately before the user places the above-mentioned toner cartridge 100 into the image forming apparatus, the user shakes the toner cartridge 100 by hand in order to cause the toner to be uniformly dispersed in the housing 101, and then pulls out the heat seal 106.
Unfortunately, the shaking of the toner cartridge 100 by the user causes the toner to adhere to the heat seal 106, and the subsequent pulling out of the heat seal 106 by the user causes the toner adhering to the heat seal 106 to be scattered around to dirty the user's hands and surroundings.